Non-isothermal analysis of the kinetics of the combustion of carbonaceous materials

López‐Fonseca, Rubén; Landa, Iratxe; Gutiérrez-Ortiz, M.A.; González‐Velasco, Juan R.

doi:10.1007/s10973-005-0614-9

Cited by 71 publications

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“…Kinetic studies carried out on similar compounds with a correctly chosen mechanism function f (α) (α is the weight fraction of material decomposed at temperature T and time t) exhibit a linear relationship between the logarithm of the preexponential factors and activation energies known as the compensation effect [1][2][3][4][5]. Several theories and explanations for such compensation behavior have been put forth [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Enthalpy-Entropy Compensation in Polyester Degradation Reactions

Al‐Mulla

2012

International Journal of Chemical Engineering

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In an earlier work the author had studied the degradation kinetics of polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and polybutylene terephthalate (PBT) under nonisothermal conditions in air and N 2 at heating rates of 5, 10, 15, and 20• C/min. In this paper the kinetic degradation parameters of PET, PTT, and PBT were estimated using the CoatsRedfern method for two different weight loss regions ranging from 2-8% (Zone I) and 8-40% (Zone II). A comparative analysis of the enthalpy-entropy compensation effect for these polyesters in air and N 2 is presented. A linear relationship was found to exist between entropy and enthalpy values. The following criteria were applied to establish an enthalpy-entropy compensation effect and to check the presence of an isokinetic temperature: (a) Exner's plot of log k 3T1 versus log k 3T2 , and (b) Krug et al. linear regression of ΔH versus ΔG. By the use of the latter two methods, varying isokinetic temperatures were obtained. These temperatures were not in the range of the experimental work conducted, indicating that these systems do not display compensation phenomena.

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Section: Introductionmentioning

confidence: 99%

Enthalpy-Entropy Compensation in Polyester Degradation Reactions

Al‐Mulla

2012

International Journal of Chemical Engineering

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“…If the kinetic studies are carried out on similar compounds and with a correctly chosen mechanism function f (α), a linear relationship between the logarithm of the pre-exponential factors and activation energies exists, known as the kinetic compensation effect (KCE), isokinetic effect, or theta rule [5][6][7][8]. Such a correlation was firstly reported in 1925 by Constable [9], in connection with his catalytic studies.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Nonisothermal Degradation of Some Polymer Composites: Change of Entropy at the Formation of the Activated Complex from the Reagents

Turmanova

Genieva

Vlaev

2011

Journal of Thermodynamics

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Studying the nonisothermal kinetics of degradation of rice husks in air or nitrogen atmosphere, polypropylene and tetrafluoroethylene-ethylene copolymer filled with different quantities of rice husks flour or the products of its thermal degradation, namely "white" or "black" rice husks ash, a linear dependence was observed between the ln A and E A , known as the kinetic compensation effect or theta rule. A linear relationship was also established between E A and the change of the entropy ΔS / = for the formation of the activated complex from the reagents. These dependences are related to the assumption of identical kinetic mechanisms of thermal degradation of the composites studied. The negative values of ΔS / = obtained show that the activated complex is a "more organized" structure than the initial reactants and that these reactions may be classified as "slow" ones. It may be concluded that the products of the thermal degradation of rice husks in a fluidized bed reactor can successfully replace the more expensive synthetic fillers to obtain different polymer composites. These polymer composites can lead to the futuristic "organic-inorganic hybrid materials" with specific properties.

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“…Like R10 monomer, R10 polymer also shows less energy for 1 st transition compared to R8. Thermogravimetry is a powerful tool in assessing thermal stability of polymers [13][14][15]. Thermal stability of the compounds is monitored using thermogravimetry and the results are used to compare the thermal stability of different structures of thiophene monomers and polymers.…”

Section: Resultsmentioning

confidence: 99%

Thermal studies on polythiophene containing mesogenic side chains

Narashimhaswamy¹,

Thelakkat²,

Schmidt³

2006

J Therm Anal Calorim

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Series of thiophenes containing mesogenic side chains at the 3 rd position are synthesized. The thermal transitions and thermal stability of the synthesized monomers and polymers are studied. The polarizing microscopic studies of synthesized monomers showed nematic liquid crystalline phase and these mesophases further confirmed by differential scanning calorimetric study. The obtained melting and the isotropic temperatures decrease linearly with the increase of aliphatic chain length. The transition temperatures determined from DSC analysis, overlap well with the temperatures obtained from optical microscopy studies. Thermal stability of the compounds is analysed using thermogravimetric studies. Thermal stability of monomers and polymers has been determined by calculating IPDT values. Structural influence on thermal degradation patterns of monomers and polymers are also discussed.

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Non-isothermal analysis of the kinetics of the combustion of carbonaceous materials

Cited by 71 publications

References 0 publications

Enthalpy-Entropy Compensation in Polyester Degradation Reactions

Enthalpy-Entropy Compensation in Polyester Degradation Reactions

Kinetics of Nonisothermal Degradation of Some Polymer Composites: Change of Entropy at the Formation of the Activated Complex from the Reagents

Thermal studies on polythiophene containing mesogenic side chains

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